Temperature dependence of the absorption coefficient of optical glasses exposed to laser radiation

Kask, Nikolai E; Radchenko, V. V.; Fedorov, G. M.; Chopornyak, D B

doi:10.1070/qe1979v009n02abeh008731

Cited by 5 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Infrared absorption of highly transmitting materials due to multiple surface scattering has previously been observed in investigations of densely packed beds of glass spheres [9] and porous media [10]. Absorption of glass is also known to be highly dependent on temperature [11]. Glass simultaneously absorbs and emits a wide range of wavelengths near the phase transition temperature [12,13].…”

Section: Through Thickness Laser Joiningmentioning

confidence: 91%

Through thickness laser joining of continuous glass fiber fabric reinforcement

Tan¹,

Satoh²,

Yao³

2012

International Congress on Applications of Lasers &Amp; Electro-Optics

View full text Add to dashboard Cite

Inter laminar crack initiation and propagation is a major failure mode in structural composite applications. Manufacturing induced fiber discontinuities within a laminate composite act as stress concentrations and initiation sites of such delamination cracks. A local inter laminar reinforcement method is proposed to mitigate the effects of manufacturing induced stress concentrations and increase the local fracture toughness of the composite. A through thickness laser fusion joining process is developed for the out of plane reinforcement of glass fiber pre-forms used in the vacuum infusion fabrication of thick composite structures. Laser joining is achieved through a thermal fusion process which joins fibers within a single bundle and fiber bundles between successive woven fabric layers. Coupled two phase heat transfer and viscous flow modeling is carried out to simulate the temperature and morphology of the joining process under experimentally observed conditions. Mode I fracture toughness of through thickness reinforced composite laminates is measured experimentally and compared to un-reinforced plane weave glass composites. Laser fusion joint effects on mode I crack propagation and fracture dynamics are observed through high resolution imaging during the crack propagation process and post mortem imaging of the fracture surface. Increased delamination resistance of laser joined composites is found to be a function of the joint thickness.

show abstract

Section: Through Thickness Laser Joiningmentioning

confidence: 91%

Through thickness laser joining of continuous glass fiber fabric reinforcement

Tan¹,

Satoh²,

Yao³

2012

International Congress on Applications of Lasers &Amp; Electro-Optics

View full text Add to dashboard Cite

show abstract

“…Infrared absorption of highly transmitting materials due to multiple surface scattering has previously been observed in investigations of densely packed beds of glass spheres [13] and porous media [14]. Absorption of glass is also known to be highly dependent on temperature [15,16]. Glass simultaneously absorbs and emits a wide range of wavelengths near the phase transition temperature [17,18].…”

Section: Methodsmentioning

confidence: 99%

Laser Joining of Continuous Glass Fiber Composite Preforms

Tan¹,

Yao

2013

Journal of Manufacturing Science and Engineering

View full text Add to dashboard Cite

A laser fusion joining method is investigated for the purpose of through thickness strengthening of fiber pre-forms used in the vacuum infusion fabrication of thick composite structures. Laser joining is achieved without filler materials to replace adhesives, pins or stitches used in conventional composite fabrication.A two step joining process is developed to fuse fibers within a single bundle and between multiple fiber bundles. Finite element analysis is used to investigate the joint strength with respect to joint morphology. Joint strength is found to be a function of the fiber contact angle and packing density at the joint interface. Tensile tests show that laser joined fiber bundles exhibit higher strength than comparable fastening methods. Lessons learned from the axial joining of fiber bundles are applied to joining in the radial and thickness directions of 3d pre-form architectures. Flow induced joint morphology and densification effects observed in the axial direction indicate the need for a two step joining process in the thickness direction. Fiber compaction effects on joint strength in the axial direction motivate the need for high fiber packing fraction at joint interfaces in the thickness direction. INTRODUCTIONComposite pre-preg fabrication involves placing densely packed resin infused tapes of reinforcement fibers in layers (laminates) and then curing to produce thin shell structures. Composite components manufactured from pre-preg processes exhibit high fiber packing fraction and high strength along the fiber directions, but offer little strength perpendicular to the fiber directions. Laminates of pre-preg construction contain no fiber reinforcements aligned in the thickness direction due to the layer by layer assembly process. Thus, pre-preg fabrication is undesirable for making composite parts requiring high through thickness strength and fracture toughness. One method for improving the through thickness strength of pre-preg constructed components is to insert metal pins through layers of pre-preg prior to curing [1,2]. Mechanical pinning increases through thickness strength, relying on matrix load transfer mechanisms between the fibers and pins. The insertion of metal pins into a stack of pre-preg lamina displaces the fibers in the lamina and introduces

show abstract

Fluorescence and glass lasers

Weber

1982

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

Temperature dependence of the absorption coefficient of optical glasses exposed to laser radiation

Cited by 5 publications

References 2 publications

Through thickness laser joining of continuous glass fiber fabric reinforcement

Through thickness laser joining of continuous glass fiber fabric reinforcement

Laser Joining of Continuous Glass Fiber Composite Preforms

Fluorescence and glass lasers

Contact Info

Product

Resources

About